Faulty camshaft position actuator position sensor on bank 1; Open or damaged signal wire between the sensor and the powertrain control module; Short to voltage on the sensor signal circuit, often from chafed insulation; Corroded, loose, or water-intruded electrical connector at the sensor or PCM; Failed camshaft position actuator solenoid allowing incorrect phasing that drives the sensor signal high; Mechanical binding or sludge in the camshaft phaser assembly affecting sensor feedback; Rarely, an internal fault in the powertrain control module

DTC codes / P03xx · Ignition system and misfire / P03E8

P03E8A Camshaft Position Actuator Position Sensor C Circuit High Bank 1

P03E8 indicates that the powertrain control module has detected an abnormally high voltage on the signal circuit for the camshaft position actuator position sensor on bank 1, sensor C. The computer expects the sensor's output to stay within a calibrated low-voltage range, and a sustained high reading tells it the circuit is open, shorted to voltage, or the sensor has failed.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or uneven engine operation as camshaft phasing control is compromised
Reduced engine power or limp-home mode triggered by the control module
Poor fuel economy or increased emissions due to incorrect valve timing
Hard starting or stalling, particularly when the engine is cold
A noticeable hesitation or surge during acceleration

Common causes, most likely first

Faulty camshaft position actuator position sensor on bank 1
Open or damaged signal wire between the sensor and the powertrain control module
Short to voltage on the sensor signal circuit, often from chafed insulation
Corroded, loose, or water-intruded electrical connector at the sensor or PCM
Failed camshaft position actuator solenoid allowing incorrect phasing that drives the sensor signal high
Mechanical binding or sludge in the camshaft phaser assembly affecting sensor feedback
Rarely, an internal fault in the powertrain control module

How to diagnose and fix it

Connect a scan tool and record freeze-frame data and any stored or pending codes before clearing anything
Visually inspect the sensor, connector, and wiring harness for damage, corrosion, or contamination
Measure sensor reference voltage and signal voltage with a digital multimeter and compare to manufacturer specifications
Perform a wiggle test on the harness while monitoring live sensor voltage to reveal intermittent opens or shorts
Check the camshaft position actuator solenoid for proper resistance and operation, as a stuck solenoid can skew sensor readings
If the circuit tests good, replace the camshaft position actuator position sensor and clear codes to verify the repair
If the fault persists, scope the signal circuit at the PCM and inspect for mechanical phaser issues before condemning the module

What a high sensor signal really tells you

A high signal voltage on this circuit is more often an open ground or a short to voltage in the harness than a failed sensor, so resistance and voltage-drop tests should precede parts replacement.
Technicians frequently replace the sensor only to find the connector pins have been pushed back or corroded, which recreates the high-voltage condition immediately after the repair.
A sticking camshaft position actuator solenoid can hold the phaser in a position that drives the sensor signal out of range, setting this code even though the sensor itself is healthy.
Oil sludge or debris in the phaser assembly can mechanically bind the actuator and produce a high sensor reading that looks electrical but is actually a lubrication maintenance issue.
This code does not always mean the engine is in immediate danger; many vehicles store it intermittently from a momentary harness rub and continue to run normally until the fault becomes continuous.

Can I keep driving with P03E8?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration, towing, or long highway trips because incorrect camshaft phasing can cause poor performance and increased emissions. If the engine runs roughly, stalls, or enters limp mode, stop driving and arrange a tow.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.